What Law Governs The Balancing Of Chemical Equations?

What Law Governs The Balancing Of Chemical Equations
The balancing of the chemical equation is based on the Law of conservation of mass. According to the law, the number of atoms of an element is equal to the on both sides of the equation. The balancing is done by placing numbers on the left side of the chemical compounds.
Law of Mass Conservation Balancing of a Chemical equation is based on the Principle of Atom Conservation (POAC) which states that the total number of atoms of each element in reactants must equal the number of atoms of that element in products. It is a derivation of law of Mass Conservation.

Which law of Conservation of mass is followed in balancing chemical equations?

Law which is followed in balancing a chemical equation is ‘Law of conservation of mass” which states that matter con not be created or distroyed and both sides (reactant side and product side) should be balanced by coefficient to ensure that this law is followed. Was this answer helpful?

What is the law of balancing?

Solved Examples – Q.1. Balance the following equation-

\( } })_2} + }_3} } }_4} \to } }_3} } }_4}} \right)_2} + }_2} }\)
Solution:
Step I: List the number of atoms of different elements present in the reactant as well as on the product side in the unbalanced chemical equation.

Element	Number of Atoms in Reactants (LHS)	Number of Atoms in Products (RHS)
\( }\)	\(1\)	\(3\)
\( }\)	\(1\)	\(2\)
\( }\)	\(6\)	\(9\)
\( }\)	\(5\)	\(2\)

Step II: In the given equation, there are three calcium atoms on the product side and one atom on the reactant side. To balance the calcium atoms, we add a \(3\) in front of the \( } })_2}\) on the left hand side. \(3 } })_2} + }_3} } }_4} \to } }_3} } }_4}} \right)_2} + }_2} }\) Step III : There is one Phosphorus atom on the reactant side and two atoms on the product side as \( } }_4}\) ions.

Element	Number of Atoms in Reactants (LHS)	Number of Atoms in Products (RHS)
\( }\)	\(3\)	\(3\)
\( }\)	\(2\)	\(2\)
\( }\)	\(14\)	\(9\)
\( }\)	\(12\)	\(2\)

Step IV: Finally, there are fourteen oxygen atoms on the left side and only nine atoms on the right side. And twelve and two hydrogen atoms on the left and right sides of the equation. So, adding a \(6\) in front of the \(\mathrm _ \mathrm \) on the right-hand side, we get- \(3 } })_2} + 2 }_3} } }_4} \to } }_3} } }_4}} \right)_2} + 6 }_2} }\) Step V: To check the correctness of the balanced equation, we count atoms of each element on both sides of the equation.

Element	Number of Atoms in Reactants (LHS)	Number of Atoms in Products (RHS)
\( }\)	\(3\)	\(3\)
\( }\)	\(2\)	\(2\)
\( }\)	\(14\)	\(14\)
\( }\)	\(12\)	\(12\)

It’s now a balanced chemical equation. The balancing of the chemical equation is based on the Law of conservation of mass. According to the law, the number of atoms of an element is equal to the on both sides of the equation. The balancing is done by placing numbers on the left side of the chemical compounds.

What is the hit-and-trial method of balancing chemical equations?

Balancing Equations – A balanced chemical equation is an equation that has equal numbers of atoms for each element both on the reactant and product sides. This is a requirement based on the Law of conservation of mass. While balancing a chemical equation, certain rules are to be followed-

The number of atoms for a given element is calculated by multiplying its coefficient with the element’s subscript in its chemical formula.
If an element appears in many formulas on one side of an equation, the number of atoms represented in each must be determined and then added.
Steps to follow while balancing equations:
Let the word-equation for the action of zinc on sulphuric acid be-
\( } + }\, } \to }\, } + }\)
The above word-equation can be represented by the following chemical equation –
\( } + }_2} } }_4} \to } }_4} + }_2}\)
Examining the number of atoms of different elements on both sides of the arrow, we get-

Element	Number of Atoms in Reactants (LHS)	Number of Atoms in Products (RHS)
\( }\)	\(1\)	\(1\)
\( }\)	\(2\)	\(2\)
\( }\)	\(1\)	\(1\)
\( }\)	\(4\)	\(4\)

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As the number of atoms of each element on the reactant and product side is the same, the equation can be considered a balanced chemical equation.

Let us take another unbalanced chemical equation and try to balance it –

\( } + }_2} } \to } }_3} }_4} + }_2}\)

Step I: Listing the number of atoms of different elements present in the reactant as well as on the product side in the unbalanced chemical equation.

Element	Number of Atoms in Reactants (LHS)	Number of Atoms in Products (RHS)
\( }\)	\(1\)	\(3\)
\( }\)	\(2\)	\(2\)
\( }\)	\(1\)	\(4\)

Step II: We must always start balancing with the compound that contains the maximum number of atoms either on the reactant or product sides. Having chosen the compound, the element with the maximum number of atoms is chosen for balancing.Using these criteria, we select \( } }_3} }_4}\) and the element oxygen in it.

Atoms of Oxygen	In Reactants	In Products
(i) Initial	\(1\left( }\, }_2} }} \right)\)	\(4\left( }\, } }_3} }_4}} \right)\)
(ii) To Balance	\(1 \times 4\)	\(4\)

To equalise the number of atoms, we must remember that we cannot alter the formulae of the compounds or elements involved in the reactions. This means the numbers in subscripts cannot be altered. However, to balance the number of atoms, stoichiometric coefficients are used.

The numerical values are placed before the compound in a chemical reaction and can vary from equation to equation for the same chemical compound. In the above equation, to balance oxygen atoms, we can put coefficient ‘\(4\)’ as \(4 }_2} }\) and not \( }_2} }_4}\) or \(\left( }_2} }}} \right)_4\). Now the partly balanced equation becomes– \( } + 4 }_2} } \to } }_3} }_4} + }_2}\) Step III: Though oxygen atoms are balanced, Fe and H atoms are still unbalanced.

Proceeding with hydrogen atoms, the number of molecules of hydrogen is made as four on the product side.

Atoms of Hydrogen	In Reactants	In Products
(i) Initial	\(8\left( }\,4 }_2 } \right)\)	\(2\left( }\, }_2}} \right)\)
(ii) To Balance	\(8\)	\(2 \times 4\)

The equation would be: \( } + 4 }_2} } \to } }_3} }_4} + 4 }_2}\) Step IV: Once hydrogen atoms are balanced, the only element left to be balanced is, iron. To equalise Fe atoms, we make it three as on the reactant side.

Atoms of Iron	In Reactants	In Products
(i) Initial	\(1 }\, }\)	\(3\left( }\, } }_3} }_4}} \right)\)
(ii) To Balance	\(1 \times 3\)	\(3\)

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\(3 } + 4 }_2} } \to } }_3} }_4} + 4 }_2}\)

Step V: To check the correctness of the balanced equation, we count atoms of each element on both sides of the equation.

\(3 } + 4 }_2} } \to } }_3} }_4} + 4 }_2}\)

The number of atoms in each element on both sides of the equation is now equal, and the equation is balanced. This approach of balancing chemical equations is known as the hit-and-trial method because we use the smallest whole number coefficient to balance the equation.

Step VI: Writing Symbols of Physical States for the compounds The physical states of the reactants and products are mentioned together with their chemical formulae to make a chemical equation more meaningful. The notations \(( }),\,( }),\,( })\) and \(( })\) is used to designate the solid, liquid, aqueous, and gaseous states, respectively.

If a reactant or product exists as a solution in water, the word aqueous \(( })\) is used. As a result, in the case above, the balanced equation is: \(3 }( }) + 4 }_2} }( }) \to } }_3} }_4}(\; }) + 4 }_2}(\; })\) The symbol (g) is used with \( }_2} }\) indicates that in this reaction, water is in the form of steam.

Which law of Conservation of mass is followed in balancing chemical equations?

Law which is followed in balancing a chemical equation is ‘ Law of conservation of mass” which states that matter con not be created or distroyed and both sides (reactant side and product side) should be balanced by coefficient to ensure that this law is followed. Was this answer helpful?

What is the importance of balancing chemical equations?

Step 3 –

Now, stoichiometric coefficients are added to molecules containing an element which has a different number of atoms in the reactant side and the product side.
The coefficient must balance the number of atoms on each side.
Generally, the stoichiometric coefficients are assigned to hydrogen and oxygen atoms last.
Now, the number of atoms of the elements on the reactant and product side must be updated.
It is important to note that the number of atoms of an element in one species must be obtained by multiplying the stoichiometric coefficient with the total number of atoms of that element present in 1 molecule of the species.
For example, when the coefficient 3 is assigned to the CO 2 molecule, the total number of oxygen atoms in CO 2 becomes 6. In this example, the coefficient is first assigned to carbon, as tabulated below.

Chemical Equation: C 3 H 8 + O 2 → 3 CO 2 + H 2 O
Reactant Side	Product Side
3 Carbon atoms from C 3 H 8	3 Carbon atoms from CO 2
8 Hydrogen atoms from C 3 H 8	2 Hydrogen atoms from H 2 O
2 Oxygen atoms from O 2	7 Oxygen atoms, 6 from CO 2 and 1 from H 2 O

What is the law of balancing?

Solved Examples – Q.1. Balance the following equation-

\( } })_2} + }_3} } }_4} \to } }_3} } }_4}} \right)_2} + }_2} }\)
Solution:
Step I: List the number of atoms of different elements present in the reactant as well as on the product side in the unbalanced chemical equation.

Element	Number of Atoms in Reactants (LHS)	Number of Atoms in Products (RHS)
\( }\)	\(1\)	\(3\)
\( }\)	\(1\)	\(2\)
\( }\)	\(6\)	\(9\)
\( }\)	\(5\)	\(2\)

Element	Number of Atoms in Reactants (LHS)	Number of Atoms in Products (RHS)
\( }\)	\(3\)	\(3\)
\( }\)	\(2\)	\(2\)
\( }\)	\(14\)	\(9\)
\( }\)	\(12\)	\(2\)

Element	Number of Atoms in Reactants (LHS)	Number of Atoms in Products (RHS)
\( }\)	\(3\)	\(3\)
\( }\)	\(2\)	\(2\)
\( }\)	\(14\)	\(14\)
\( }\)	\(12\)	\(12\)

How to check the correctness of a balanced chemical equation?

Step V: To check the correctness of the balanced equation, we count atoms of each element on both sides of the equation. It’s now a balanced chemical equation. The balancing of the chemical equation is based on the Law of conservation of mass. According to the law, the number of atoms of an element is equal to the on both sides of the equation.